Big Bang (origin of the Universe) that occured about 13.8 billion years ago is pretty much an established experimental fact, drawing on many astronomical observations. However, these observations rely on light - more precisely on electromagnetic radiation - and so come from about 380,000 years and later after the Big Bang. Only after this time light - electromagnetic radiation - ceased to be absorbed and the Universe became transparent. To understand the very early moments after the Big Bang we need to recreate the intensely hot conditions at that time. We can do this in particle colliders; at the world’s largest particle accelerator, the LHC at CERN, we can reach trillions of degrees, corresponding to 10 millionths part of a second after the Big Bang. We try to understand how the Universe evolved from this early stage and how we got where we are today.
Karel Šafařík (CZE)
A nuclear physicist, former coordinator at the ALICE experiment at CERN.